Merge pull request #1769 from 0xbe7a/fix-additional_zip_keys

save default values additional_zip_keys for subsequent migrations

conda_smithy/variant_algebra.py

@@ -133,6 +133,12 @@ def op_variant_key_add(v1: dict, v2: dict):
     primary_key = v2["__migrator"]["primary_key"]
     additional_zip_keys = v2["__migrator"].get("additional_zip_keys", [])
 
+    ordering = v2["__migrator"].get("ordering", {})
+    if primary_key not in v2:
+        return v1
+    if primary_key not in v1:
+        raise RuntimeError("unhandled")
+
     newly_added_zip_keys = set()
 
     result = v1.copy()
@@ -155,11 +161,13 @@ def op_variant_key_add(v1: dict, v2: dict):
             )
             newly_added_zip_keys.update([primary_key] + additional_zip_keys)
 
-    ordering = v2["__migrator"].get("ordering", {})
-    if primary_key not in v2:
-        return v1
-    if primary_key not in v1:
-        raise RuntimeError("unhandled")
+    for key in newly_added_zip_keys:
+        # store the default value for the key, so that subsequent
+        # key additions don't need to specify them and continue to use the default value
+        # assert len(v1[key]) == 1
+        result.setdefault("__additional_zip_keys_default_values", {})[
+            additional_key
+        ] = result[additional_key][0]
 
     for pkey_ind, pkey_val in enumerate(v2[primary_key]):
         # object is present already, ignore everything
@@ -188,16 +196,27 @@ def op_variant_key_add(v1: dict, v2: dict):
                         continue
 
                     # Transform key to zip_key if required
-                    # assert len(v1[key]) == 1
                     if key in newly_added_zip_keys:
-                        result[key] = [result[key][0]] * len(new_keys)
+                        default_value = result[
+                            "__additional_zip_keys_default_values"
+                        ][key]
+                        result[key] = [default_value] * len(new_keys)
 
                     # Create a new version of the key from
                     # assert len(v2[key]) == 1
                     new_value = [None] * len(new_keys)
                     for i, j in position_map.items():
                         new_value[j] = result[key][i]
-                    new_value[new_key_position] = v2[key][pkey_ind]
+
+                    if key in v2:
+                        new_value[new_key_position] = v2[key][pkey_ind]
+                    elif key in result.get(
+                        "__additional_zip_keys_default_values", {}
+                    ):
+                        new_value[new_key_position] = result[
+                            "__additional_zip_keys_default_values"
+                        ][key]
+
                     result[key] = new_value
 
     return result

news/1769-fix-additional_zip_keys.rst

@@ -0,0 +1,23 @@
+**Added:**
+
+* <news item>
+
+**Changed:**
+
+* <news item>
+
+**Deprecated:**
+
+* <news item>
+
+**Removed:**
+
+* <news item>
+
+**Fixed:**
+
+* Fixed additional_zip_keys, so that subsequent migrations don't break.
+
+**Security:**
+
+* <news item>